Collaborative Research: Promoting Lithium Sulfides Redox Cycle via Atomically Dispersed Active Sites for Batteries

合作研究：通过电池的原子分散活性位点促进硫化锂氧化还原循环

• 批准号: 2129982
• 负责人: Bin Wang
• 金额: $ 25.56万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2129982&HistoricalAwards=false
• 关键词: Collaborative; Research; Promoting; Lithium; Sulfides

Batteries play a key role in information technology, energy storage, and reduction in carbon emissions. The lithium-sulfur battery uses earth-abundant sulfur as the cathode material and delivers more energy than the current batteries, thus it is considered as one of the next-generation technologies. However, its chemistry of converting between sulfur and lithium sulfides is a very complex process and has fundamental problems that result in low capacity and short battery lifetime, such as the dissolution of intermediate products and their shuttling between the two electrodes. Recent evidence has shown the critical role of single-atom catalysts in promoting this conversion process and subsequently boosting the battery performance, but the fundamental understanding of the active catalytic sites and the reaction mechanism remains very elusive. This hinders the development of a catalyst-functionalized cathode structure with much improved performance. The current project will fill this knowledge gap, thus accelerating the development of a practical lithium-sulfur battery technology to serve the national interest in the key energy storage applications. The project will also result in societal boarder impacts. The knowledge gained on single-atom catalysts can be applied to other electrochemical systems. Graduate and undergraduate students, including those from underrepresented groups, will be trained in the fields of advanced material science and battery technology. The research outcomes will be incorporated into the elective courses. The research teams will reach out to the local communities, recruiting high school students to conduct research and delivering public lectures on the new battery technology to local public libraries. This collaborative fundamental research project will attain theoretical understanding and experimental validation of the structure-property correlation of atomically dispersed catalysts in promoting lithium sulfides redox cycle, and to transform these understandings into an optimized sulfur cathode design. The project hypothesizes that the electronic structure of the single-atom catalyst, which is determined by both the metal center and its local coordination, can be tuned for binding polysulfides and activating the Li-S and S-S bonds with an optimized strength, thus significantly improving the landscape of sulfides conversion while preventing polysulfides shuttling. To this end, combining theoretical calculations and modeling with in-situ/ex-situ experimental studies, this project will establish the structure-property correlation of single-atom catalysts in chemisorbing polysulfides and activating the Li-S and S-S bonds for conversion, and probe and visualize the evolution of the electrode morphology and its chemical distribution during cycling. The studies will thus provide insights on the choice of the metal center, its local coordination, and the electrolyte in the proximity, and reveal their impacts on the lithium sulfides redox cycle. These understandings of single-atom catalyst functions on sulfides binding and conversion, both thermodynamically and kinetically, assisted by advanced characterization tools, will then be leveraged to design advanced sulfur cathode structures, functionalized with single-atom catalysts, for demonstration of battery cells with much-improved performance.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

电池在信息技术，储能和碳排放量减少中起着关键作用。锂硫电池用作阴极材料的土壤含量，并提供比当前电池更多的能量，因此被认为是下一代技术之一。但是，其在硫和硫化锂之间转化的化学反应是一个非常复杂的过程，并且具有基本问题，可导致容量较低和电池寿命短，例如中间产品的溶解及其在两个电极之间的穿梭。 最近的证据表明，单原子催化剂在促进这种转换过程并随后提高电池性能中的关键作用，但是对主动催化位点的基本理解和反应机制仍然非常难以捉摸。 这阻碍了催化剂官能化的阴极结构的发展，其性能大大提高。当前的项目将填补这一知识差距，从而加快实用锂硫电池技术的开发，以在关键的能源存储应用中为国家利益服务。该项目还将导致社会寄宿生的影响。在单原子催化剂上获得的知识可以应用于其他电化学系统。研究生和本科生，包括来自代表性不足的团体的研究生和本科生，将在先进的材料科学和电池技术领域接受培训。研究成果将纳入选修课程。 研究团队将与当地社区接触，招募高中生，向当地公共图书馆进行有关新电池技术的研究并进行公开讲座。该协作基本研究项目将对促进硫化锂氧化还原循环的原子分散催化剂的结构特性相关性获得理论理解和实验验证，并将这些理解转化为优化的硫阴极设计。该项目假设由金属中心及其局部协调确定的单原子催化剂的电子结构可以调节以结合多硫化物的结合并以优化的强度激活LI-S和S-S键，从而显着改善了硫化物景观的固体转化率，同时可以防止多硫化物撞车撞车。为此，将理论计算和建模与原位/EX-SITU实验研究相结合，该项目将建立化学溶剂硫化物中单原子催化剂的结构 - 主体相关性，并激活Li-S和S-S-S-S-S-S-S-S-S-S键进行转换，并探测并在其化学物质和其化学物质的演化中探测和可视化。因此，研究将提供有关金属中心选择，局部协调和接近电解质的见解，并揭示其对硫化锂氧化还原循环的影响。这些对单原子催化剂在热力学和运动上的结合和转化的理解，无论是在热力学和运动上，在先进的特征工具的辅助下，都将被利用来设计高级硫磺阴极结构，该结构通过单原子催化剂功能来官能化，并通过多个促进性能来证明均具有反映nsf deem的奖励性能。优点和更广泛的影响审查标准。

项目成果

Ion transport phenomena in electrode materials

• DOI: 10.1063/5.0138282
• 发表时间: 2023-06
• 期刊: Chemical Physics Reviews
• 作者: Jing Wen;Xinzhi Ma;Lu Li;Xitian Zhang;Bin Wang